The present invention relates to a process to manufacture, in laboratory and/or industrial scale, mineral or synthetic or silicon lubricant greases, in which hydrophilic or hydrophobic silicon bioxide (fume silica) or precipitated and ground silicic acid are mixed with mineral oils or vegetable oils or synthetic esters or silicon oils or glycerine or propylene glycol at relatively low temperatures and pressures, including atmospheric pressures. As a result the control of the mixture as well as the control of the thickening or polymerization reaction are facilitated. The polymerization or thickening reaction may be carried out in a short time, in contrast to the process known up to now for the manufacture of metallic soap lubricant greases such as sodium, calcium, lithium, magnesium, aluminum and polyureas, in which the saponification of polymerization reaction is carried out at high pressures and temperatures in a considerably greater time, involving high manufacturing costs.
In the previous art, there are some processes that use silicon bioxide as a thickener, such as the process described in U.S. Pat. No. 4,378,297, in which lubricant sealers which are resistant to solvents such as chloroform and carbon disulfide are prepared by forming a ethylene glycol and a minor amount of water.
U.S. Pat. No. 4,701,272 discloses a silicon grease composition containing methylphenyl polysiloxane having a specific phenyl content hydrophilic fumed silica having a specific surface area of at least 130 m.sup.2 /g, and an alkoxy containing organosiloxane compound. Likewise, South African Patent No. 86/0555 discloses a grease containing a suitable polypropylene glycol, a thickener comprising finely particulate silicon and an extreme pressure functional additive.
However, the greases obtained from these mentioned processes have limited characteristics.